Integrative Visuomotor Behavior is Associated with Interregionally Coherent Oscillations in the Human Brain. Joseph Classen, Christian Gerloff, Manabu Honda, Mark Hallett. Human Motor Control Section, Medical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, U.S.A.
APStracts 4:318N, 1997.
ABSTRACT
Coherent electrical brain activity has been demonstrated to be associated with perceptual events in mammals. It is unclear whether it is also a mechanism instrumental in the performance of sensorimotor tasks requiring the continuous processing of information between primarily executive and receptive brain areas. In particular it is unknown whether interregional coherent activity detectable in electroencephalographic (EEG) recordings on the scalp reflects interareal functional cooperativity in humans. We studied patterns of changes in EEG-coherence associated with a visuomotor force-tracking task in seven subjects. Interregional coherence of EEG signals recorded from scalp regions overlying the visual and the motor cortex increased in comparison to a resting condition when subjects tracked a visual target by producing an isometric force with their right index finger. Coherence between visual and motor cortex decreased when the subjects produced a similar motor output in the presence of a visual distractor, and was unchanged in a purely visual and purely motor task. Increases and decreases of coherence were best differentiated in the low beta frequency range (13-21 Hz). This observation suggests a special functional significance of low frequency oscillations in information processing in large-scale networks. These findings substantiate the view that coherent brain activity underlies integrative sensorimotor behavior. 

Received 22 January 1997; accepted in final form 4 November 1997.
APS Manuscript Number J54-7.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 12 December 1997